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On the use of experimental diets for physiological studies of hydrozoans

  • Steve Dudgeon (a1), Kylla M. Benes (a1), Stacy A. Krueger (a1), Janet Kübler (a1), Paul Mroz (a1) (a2) and Christin T. Slaughter (a1) (a3)...


Recent studies of hydrozoans suggest that metabolic factors associated with the physiology of gastrovascular fluid transport play a role in regulating morphogenetic development of colonies. In that context, the objective of this study was to develop a system to experimentally control diets of hydrozoans in culture that could be used to test effects of specific compounds. This diet delivery system consisted of a known concentration of homogenate of brine shrimp nauplii that was solidified in a 1% agar block cut to the size of, and containing the equivalent of, a single, 2-day old brine shrimp nauplius larva. We tested the utility of this system by comparing the frequencies of ingestion, and rates of gastrovascular transport and growth following feeding, between polyps of Podocoryna carnea fed either a single brine shrimp nauplius (controls) or an agar cube including brine shrimp homogenate. Polyps fed experimental diets showed similar rates of gastrovascular transport (6 and 12 h after feeding) and growth (24 h after feeding) to those of polyps fed a brine shrimp nauplius suggesting that no significant artefacts existed associated with these response variables. However, the frequency of ingestion of experimental foods by polyps was much less than that by control polyps. These results imply that this system of delivery of experimental diets has potential as a means to manipulate physiological state and assay the effects on morphogenesis of hydrozoan colonies, but must first overcome limitations of low ingestion frequency.


Corresponding author

Correspondence should be addressed to: S. Dudgeon, Department of Biology, California State University, Northridge, CA 91330-8303, USA email:


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Blackstone, N.W. (1996). Gastrovascular flow and colony development in two colonial hydroids. Biological Bulletin. Marine Biological Laboratory, Woods Hole 190, 5668.
Blackstone, N.W. (1998). Physiological and metabolic aspects of experimental heterochrony in colonial hydroids. Journal of Evolutionary Biology 11, 421438.
Blackstone, N.W. (1999). Redox control in development and evolution: evidence from colonial hydroids. Journal of Experimental Biology 202, 35413553.
Blackstone, N.W. (2001). Redox state, reactive oxygen species, and adaptive growth in colonial hydroids. Journal of Experimental Biology 204, 18451853.
Blackstone, N.W. (2003). Redox signaling in the growth and development of colonial hydroids. Journal of Experimental Biology 206, 651658.
Blackstone, N.W. and Buss, L.W. (1992). Treatment with 2,4-dinitrophenol mimics ontogenetic and phylogenetic changes in a hydractiniid hydroid. Proceedings of the National Academy of Sciences of the United States of America 89, 40574061.
Blackstone, N.W. and Buss, L.W. (1993). Experimental heterochrony in hydractiniid hydroids: why mechanisms matter. Journal of Evolutionary Biology 6, 307327.
Bruno, J.F. and Edmunds, P.J. (1997). Clonal variation for phenotypic plasticity in the coral Madracis mirabilis. Ecology 78, 21772190.
Cheetham, A.H., Jackson, J.B.C. and Hayek, L.A.C. (1995). Quantitative genetics of bryozoan phenotypic evolution. 3. Phenotypic plasticity and the maintenance of genetic variation. Evolution 49, 290296.
Cheplick, G.P. (1995). Genotypic variation and plasticity of clonal growth in relation to nutrient availability in Amphibromus scabrivalvis. Journal of Ecology 83, 459468.
Crowell, S. (1974). Morphogenetic events associated with stolon elongation in colonial hydroids. American Zoologist 14, 665672.
Doolen, J.F., Geddes, G.C. and Blackstone, N.W. (2007). Multicellular redox regulation in an early-evolving animal treated with glutathione. Physiological and Biochemical Zoology 80, 317325.
Dudgeon, S.R. (2001). Hydrozoans: colony integration and the control of morphological plasticity. In Kaandorp, J. and Kübler, J.E. (eds) The algorithmic beauty of corals, sponges and seaweeds. Berlin, Germany: Springer-Verlag, pp.4348.
Dudgeon, S.R. and Buss, L.W. (1996). Growing with the flow: on the maintenance and malleability of colony form in the hydroid Hydractinia. The American Naturalist 147, 667691.
Dudgeon, S.R., Wagner, A., Vaisnys, J.R. and Buss, L.W. (1999). Dynamics of gastrovascular circulation in the hydrozoan Podocoryne carnea: the one polyp case. Biological Bulletin. Marine Biological Laboratory, Woods Hole 196, 117.
Harvell, C.D. (1991). Coloniality and inducible polymorphism: the interaction of zooid and colony level control. The American Naturalist 138, 114.
Jackson, J.B.C. (1979). Morphological strategies of sessile animals. In Larwood, G. and Rosen, B.R. (eds) Biology and systematics of colonial organisms. London and New York: Academic Press, pp. 499555. [Systematics Association Special Volume No. 11.]
Lenhoff, H.M. (1961). Activation of the feeding reflex in Hydra littoralis. Journal of General Physiology 45, 331344.
Loomis, W.F. (1955). Glutathione control of the specific feeding reaction of Hydra. Annals of the New York Academy of Science 62, 209228.
Pierobon, P., De Petrocellis, L., Minei, R. and DiMarzo, V. (1997). Arachidonic acid as an endogenous signal for the glutathione-induced feeding response in Hydra. Cellular Molecular Life Sciences 53, 6168.
Wagner, A., Dudgeon, S.R., Vaisnys, J.R. and Buss, L.W. (1998). Non-linear oscillations in polyps of the colonial hydroid Podocoryne carnea. Naturwissenschaften 85, 15.


On the use of experimental diets for physiological studies of hydrozoans

  • Steve Dudgeon (a1), Kylla M. Benes (a1), Stacy A. Krueger (a1), Janet Kübler (a1), Paul Mroz (a1) (a2) and Christin T. Slaughter (a1) (a3)...


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